Photoplethysmogram (PPG) signal obtained at the fingertip indicates a volumetric fluctuation of blood in finger arterioles. The PPG waveform is periodic in nature and its fundamental frequency indicates the heart rate (HR). There has been a growth of development of technologies for real-time monitoring of vital signs using PPG signal captured using wearable devices, as PPG has important information which can be correlated to certain symptoms and diseases. However, PPG signals are prone to noise, due to motion artefacts, poor blood perfusion and changes in ambient light. These artefacts impede the usability of PPG signal in real-time assessment/monitoring applications like false alarms in an Intensive Care Unit (ICU), inaccuracy in vital measurements like blood pressure, screening of other diseases, and so on. Hence, it is important to check quality of continuous PPG signal before measuring vitals. Also, in home care or rural setup, where people are not trained to collect PPG data, a real-time feedback of signal quality can help to capture clean signal.